i'm using image_filter resize in nginx to resize a bunch of images that are in Amazon S3. I want to be able to save the resized image so that for the 2nd and subsequent request for the image it doesn't need to get resized. I have worked out how to cache the original image in Nginx so at least the image isn't continuously retrieved from S3 but i can't work out how to cache the resized image on the nginx server. Is this possible?

here's the relevant part of my nginx config (all this server does is resize images):